1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * 4 * Copyright (C) 2011 Novell Inc. 5 * Copyright (C) 2016 Red Hat, Inc. 6 */ 7 8 struct ovl_config { 9 char *lowerdir; 10 char *upperdir; 11 char *workdir; 12 bool default_permissions; 13 bool redirect_dir; 14 bool redirect_follow; 15 const char *redirect_mode; 16 bool index; 17 bool nfs_export; 18 int xino; 19 bool metacopy; 20 }; 21 22 struct ovl_sb { 23 struct super_block *sb; 24 dev_t pseudo_dev; 25 /* Unusable (conflicting) uuid */ 26 bool bad_uuid; 27 }; 28 29 struct ovl_layer { 30 struct vfsmount *mnt; 31 /* Trap in ovl inode cache */ 32 struct inode *trap; 33 struct ovl_sb *fs; 34 /* Index of this layer in fs root (upper idx == 0) */ 35 int idx; 36 /* One fsid per unique underlying sb (upper fsid == 0) */ 37 int fsid; 38 }; 39 40 struct ovl_path { 41 struct ovl_layer *layer; 42 struct dentry *dentry; 43 }; 44 45 /* private information held for overlayfs's superblock */ 46 struct ovl_fs { 47 struct vfsmount *upper_mnt; 48 unsigned int numlower; 49 /* Number of unique lower sb that differ from upper sb */ 50 unsigned int numlowerfs; 51 struct ovl_layer *lower_layers; 52 struct ovl_sb *lower_fs; 53 /* workbasedir is the path at workdir= mount option */ 54 struct dentry *workbasedir; 55 /* workdir is the 'work' directory under workbasedir */ 56 struct dentry *workdir; 57 /* index directory listing overlay inodes by origin file handle */ 58 struct dentry *indexdir; 59 long namelen; 60 /* pathnames of lower and upper dirs, for show_options */ 61 struct ovl_config config; 62 /* creds of process who forced instantiation of super block */ 63 const struct cred *creator_cred; 64 bool tmpfile; 65 bool noxattr; 66 /* Did we take the inuse lock? */ 67 bool upperdir_locked; 68 bool workdir_locked; 69 /* Traps in ovl inode cache */ 70 struct inode *upperdir_trap; 71 struct inode *workbasedir_trap; 72 struct inode *workdir_trap; 73 struct inode *indexdir_trap; 74 /* Inode numbers in all layers do not use the high xino_bits */ 75 unsigned int xino_bits; 76 }; 77 78 /* private information held for every overlayfs dentry */ 79 struct ovl_entry { 80 union { 81 struct { 82 unsigned long flags; 83 }; 84 struct rcu_head rcu; 85 }; 86 unsigned numlower; 87 struct ovl_path lowerstack[]; 88 }; 89 90 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 91 92 static inline struct ovl_entry *OVL_E(struct dentry *dentry) 93 { 94 return (struct ovl_entry *) dentry->d_fsdata; 95 } 96 97 struct ovl_inode { 98 union { 99 struct ovl_dir_cache *cache; /* directory */ 100 struct inode *lowerdata; /* regular file */ 101 }; 102 const char *redirect; 103 u64 version; 104 unsigned long flags; 105 struct inode vfs_inode; 106 struct dentry *__upperdentry; 107 struct inode *lower; 108 109 /* synchronize copy up and more */ 110 struct mutex lock; 111 }; 112 113 static inline struct ovl_inode *OVL_I(struct inode *inode) 114 { 115 return container_of(inode, struct ovl_inode, vfs_inode); 116 } 117 118 static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) 119 { 120 return READ_ONCE(oi->__upperdentry); 121 } 122